Increase in heart rate precedes episodes of ventricular tachycardia and ventricular fibrillation in patients with implantable cardioverter defibrillators: Analysis of spontaneous ventricular tachycardia database

Jan Nemec, Stephen C. Hammill, Win Kuang Shen

Research output: Contribution to journalArticle

39 Scopus citations

Abstract

Patients with heart disease and decreased heart rate variability (HRV) have an increased risk of all-cause mortality as well as arrhythmic death. The question of acute changes in HRV immediately preceding arrhythmic events remains unanswered. We analyzed data from patients with implantable cardioverter defibrillators who had ventricular tachycardia (VT) or ventricular fibrillation (VF) detected by the device. The device stores 1,000 consecutive RR intervals preceding the arrhythmic event detection and before device interrogation. Compared to this control segment, the mean heart rate (HR) increased prior to the arrhythmic event for both VT (88.5 vs 72.7 beats/min, P < 0.0005) and VF (85.4 vs 73.3 beats/min, P < 0.05) patients. No difference in HRV (as analyzed by a time-domain, frequency-domain [fast Fourier transform], and a nonlinear technique) has been detected. We estimated the amount of ectopic beats from the number of RR intervals that differed from the preceding RR interval by > 10%. The frequency of such beats was significantly higher in the prearrhythmic data segments than in the control segments for VT (10.7 vs 6.6/50 beats, P < 0.05) although not for VF (9.8 vs 6.1/50 beats, NS). We conclude that the HR and frequency of ectopic beats are higher prior to onset of the arrhythmic events, although HRV does not change markedly. These results are consistent with sympathetic activation being the predominant autonomic change prior to VT/VF onset in this patient population.

Original languageEnglish (US)
Pages (from-to)1729-1738
Number of pages10
JournalPACE - Pacing and Clinical Electrophysiology
Volume22
Issue number12
DOIs
StatePublished - Jan 1 1999

Keywords

  • Heart rate
  • Heart rate variability
  • ICD
  • Sudden cardiac death
  • Ventricular tachycardia

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Fingerprint Dive into the research topics of 'Increase in heart rate precedes episodes of ventricular tachycardia and ventricular fibrillation in patients with implantable cardioverter defibrillators: Analysis of spontaneous ventricular tachycardia database'. Together they form a unique fingerprint.

  • Cite this